Load-brake apparatus.



No. 762,962. I PATENTED JUNE 21, 1904.

w. v. TURNER-6: R. H, BLA'GKALL'. i

LOAD BRAKE APPARATUS. APPLIGATION run) on. 20, 1903'.

N0 MODEL.

UNiTaD STATES WALTER V. TURNER, OF VVILKINSBURG, AND ROBERT H. BLACKALL,OF I EDGEVVOOD PARK, PENNSYLVANIA, 'ASSIGNORS TO THE VVESTINGr-'Patented June 21, 1904.

PATENT OFFICE.

HOUSE AIR BRAKE COMPANY, OF PITTSBURG, PENNSYLVANIA, A CORPORATION OFPENNSYLVANIA.

LOAD-BRAKE APPARATUS.

SPECIFICATION forming part of Letters Patent No. 762,962, dated June 21,1904:.

Application filed October20,1903. Serial No. 177,773. (Nomodeld To all,whmn it may concern:

Be it known that W e, WALTER V. TURNER, residing at WV ilkinsburg, andROBERT H. BLACK- ALL, residing at Edgewood Park, in the county ofAllegheny and State of Pennsylvania, citizens of the United States, haveinvented a certain new and useful Improvement in Load- Brake Apparatus,of which the following is a specification.

This invention relates to automatic fluidpressure brake apparatus forcars, and has for its object to provide an improved device by means ofwhich the braking power may be adjusted either for light braking, as onempty cars,-or for heavy braking, as on loaded cars.

With the present capacity of freight-cars, many of which are built tocarry loads equal to several times the weight of the car when empty, itis necessary in order to secure eflicient braking to provide means foradjusting the braking power according to the load on the car, since, asis well known, a much greater braking pressure may be applied to thewheels of the car when heavily loaded than when empty without danger ofsliding the wheels. Various devices for this purpose have heretoforebeen proposed, and some of these have employed a pressure-reducing valveinserted is designed to normally give a high braking in the passageleading from the triple-valve device to the brake-cylinder for limitingthe pressure therein to any desired amount for light-load braking; butsuch devices are subject to the objection that. the passage to thebrake-cylinder is more or less obstructed so as to interfere with thefree venting of the train-pipe to the brake-cylinder in emergencyapplications of the brakes, and thus preventing the successful operationof the all-important quick-action feature of the present standardair-brake system.

According to this invention the apparatus pressurc that is, the relativesizes of the auxiliary reservoir, brake-cylinder, triplevalve ports, andthe degree of pressure carriedare calculated to give a brake-cylinderpressure adequate for braking the car when loaded-while a regulating orreducing valve operated by the brake cylinder pressure is interposed inthe passage leading from the triple valve to the brake-cylinder forlimiting the pressure admitted thereto to any desired amount, avalve-controlled by-pass being provided around said reducing-valve forcutting the same into or out of action, according as the car is empty orloaded. Another valve device, which operates only upon an emergencyapplication of the brake, is also provided for opening a straightpassage to the brake-cylinder around the reducing-valve.

The accompanying drawing illustrates this invention as applied to a carequipment of the standard Westinghouse air-brake apparatus,

the additional'valve devices and pipe connections comprising thisimprovement being shown in section.

Referring to the structure as shown in the drawing, the triple-valvedevice '1 is of the standard VVestinghonse quick-action type, which isadapted to vent fluid under pressure from the train-pipe to thebrake-cylinder in emergency applications and is provided with theusualbrake-cylinder port 2 and pipe connection 3, leading to the auxiliaryreservoir I. In the passage or pipe connection 5, leading fromthe port 2of the triple valve to the brake-cylinder 6, is located apressure-reducing valve device 7, which may be of any desiredconstruction, but is here shown of an ordinary form comprising adiaphragm-piston 8, exposed on one side to brake-cylinder pressure andsubject on the opposite side to the pressure of an adjustable spring 9for opcrating the spring-pressed valve 10, which controls thebrake-cylinder passage.

In order to secure quick action in an emergency application of thebrakes, an emergencyvalve device is provided for opening a straightpassage around thereducin'g-valve to the brake-cylinder, and althoughany form of means for securing this result is within the scope of thisinvention for the purposes of [usual way.

illustration we have shown a valve device 11, having a ported piston 12therein and connected on opposite sides of the piston to thebrake-cylinder passage or pipe 5, said piston being connected toslide-valve 13 for opening direct port 1 1, communicating with astraight passage or pipe 15, leading to the brake-cylinder around thereducing-valve.

The port 16 through the piston 12 is made of substantially the same sizeas the graduating-port of the triple-valve device, so that in allservice applications of the brakes on empty cars the air will flow fromthe triple valve through this port 16 in piston 12 and through pipe 5and the reducing-valve to the brake-cylinder without causing anymovement of the piston 12, a light spring 17 being provided for normallyholding the piston and valve 13 in position with the direct port 14closed.

A by-pass or pipe connection 18, having a valve 19, is provided aroundthe reducingvalve and emergency-valve device for opening a freecommunication from the triple valve to the brake cylinder in heavybraking for loaded cars.

The operation of this improved device is as follows, the valve or cock19 being adjusted to its closed position for giving light braking forempty cars and the spring 9 of the reducing-valve being set forthe'maximu'm pressure (thirty pounds, for instance) it is desired toadmit to the brake-cylinder for light braking. When a serviceapplication of the brakes is made, air under pressure passes throughport 16, pipe 5, and the reducing-valve to the brake-cylinder, and if asufficient reduction of train-plpe pressure is made for securing a heavyservice application the brake-cylinder pressure will increase until thedesired maximum for which the reducing-valve is set is reached, when thevalve 10 closes, preventing any further increase in the brake-cylinderpressure on the light or empty cars. Further reductions of train-pipepressure cause an increase of brake-cylinder pressure in the usual wayon all cars on which the valves 19 of the by-pass pipes 18 are open forheavy braking. When the brakes are released, the brake-cylinder pressureon empty cars raises valve 10 and passes to the atmosphere through pipe5, port 16, and the triple-valve exhaust in the When an emergencyapplication of the brakes is made and the triple-valve device operatesto vent train pipe .air to the brake-cylinder, this air flows throughthe port 2 and into the passage 5 much more rapidly than it can passthrough the comparatively small port 16 in piston 12. Consequently thepressure accumulating on the face of the piston causes it to move backagainst the light spring 17 and instantly open the direct port 14 andstraight passage 15 to the brake-cylinder, thus providing a free andwide-open passage direct to the brake-cylinder in emergencyapplications. By this means the train-pipe air has a free access to thebrake-cylinder when the triple valve is moved to emergency position andis locally vented at each triple valve with sufiicient rapidity tosecure the serial quick action of all the brakes throughout the train.

When the valve 19 is adjusted to its open position to establish freecommunication from the triple valve to the brake-cylinder throughby-pass pipe 18, as on loaded cars for heavy braking, thepressure-reducing valve is cut out of action, and the brake is appliedand released in the usual way.

It will now be seen that by means of this improvement a heavy brakingpressure may be obtained on loaded cars, while on empty cars the maximumbrake-cylinder pressure may be limited to any desired amount by thesimple turning of a cock, at the same time retaining the importantquick-action feature of the triple valves on empty cars on which theapparatus is adjusted for light-load braking.

Having now described our invention, what we claim as new, and desire tosecure by Letters Patent, is

1. A load-brake apparatus comprising a regulating or pressure-reducingvalve for limiting the brake-cylinder pressure, and a valve-controlledby-pass around said reducing-valve.

2. A load-brake apparatus comprising a regulating or reducing valveoperated by brakecylinder pressure for limiting said pressure to acertain amount in service applications and a valve-controlled by-passaround said reducing-valve.

3. In a fluid-pressure brake the combination with a train-pipe,auxiliary reservoir, triple valve and brake-cylinder, of areducing-valve located in the passage from the triple valve to thebrake-cylinder, and a valve-controlled by-pass around saidreducing-valve.

4. A load-brake apparatus comprising a reducing-valve for limiting thebrake-cylinder pressure to a certain amount in service applications, andan emergency-valve device operated by an emergency application of thebrakes for opening a direct passage to the brake-cylinder around thereducing-valve.

5. A load-brake apparatus comprising a re ducing-valve for limiting thebrake-cylinder pressure to a certain amount in service applications, andan emergency-valve device operated by the flow of air from thetrain-pipe to the brake-cylinder in emergency applications for opening adirect passage to the brake-cylinder around the reducing-valve.

6. In a fluid-pressure brake the combination with a train-pipe,auxiliary reservoir, triple valve and brake-cylinder, of areducing-valve inserted in the passage from the triple valve to thebrake-cylinder, and an emergencyvalve device also located in saidpassage and operated by the flow of air from the trainpipe to open adirect passage around the reducing-valve to the brake-cylinder.

7 1n a fluid-pressure brake the combination with a train-pipe, auxiliaryreservoir; triple Valve and brake-cylinder, of a reducing-valve locatedin the passage from the triple valve to the brake-cylinder, anemergency-valve device for opening a direct passage around thereducing-valve to the brake-cylinder and a valve controlled by-passaround both of said valve devices.

8. In a fluid-pressure brake the combination with a train pipe,auxiliary reservoir, triple valve and brake-cylinder, of areducing-valve located in the passage from the triple valve from thetrain-pipe t0 the brake-cylinder for opening said direct passage inemergency applications.

In testimony whereof We have hereunto set our hands.

WALTER V. TURNER. ROBERT H. BLACKALL.

Witnesses:

GEO. B. SNYDER, JAs. B. MACDONALD.

